Polyacrylates containing flame retardant

ABSTRACT

PLASTIC COMPOSITIONS CONTAINING POLYACRYLATES AND BISPHENOXY COMPOUNDS HAVING THE FORMING:   (((A)I,(Z)M-PHENYL)-O-(ALKYLENE)-O-),(A)I&#39;&#39;,(Z)M&#39;&#39;-BENZENE   WHEREIN Z IS BROMINE, M AND M&#39;&#39; ARE INTEGERS HAVING A VALUE OF 1-4, I AND I&#39;&#39; ARE INTEGERS HAVING A VALVE OF 1 OR 2, ALKYLENE IS A STRAIGHT OR BRANCHED CHAIN ALKYLENE GROUP HAVING FROM 1 TO 6 CARBON ATOMS AND A IS CYANO, NITRO, LOWER ALKOXY, LOWER ALKYL, FLUORINE, DIALKYLAMINO, PHENYL, HALO-PHENYL, BENZYL OR HALO-BENZYL.

United States Patent 015% US. Cl. 260-453 R 17 Claims ABSTRACT OF THEDISCLOSURE Plastic compositions containing polyacrylates and bis phenoxycompounds having the formula:

wherein Z is bromine, m and m' are integers having a value of 1-4, i andi' are integers having a value of 1 or 2, alkylene is a straight orbranched chain alkylene group having from 1 to 6 carbon atoms and A iscyano, nitro, lower alkoxy, lower alkyl, fluorine, dialkylamino, phenyl,halo-phenyl, benzyl or halo-benzyl.

This application is a continuation-in-part of copending application Ser.No. 260,240, filed June 6, 1972 and now abandoned. The entirespecification of this case, Ser. No. 260,240, is to be considered asincorporated herein by reference.

The prior art considered in conjunction with the preparation of thisapplication is as follows: US. 2,130,990; US. 2,186,367, US. 2,329,033;US. 3,666,692; US. 3,686,320; US. 3,658,634; German Pat. No. 1,139,636;German Pat. No. 2,054,522; Japanese Pat. No. (72) 14,500 as cited invol. 77, Chemical Abstracts, col. 153737k (1972); Chemical Abstracts,vol. 13, col. 448 Chemical Abstracts, vol. 31, col. 7045 and Journal ofthe Chemical Society, pp. 2972-2976 (1963). All of these publicationsare to be considered as incorporated herein by reference.

The present invention relates to plastic compositions containingpolyacrylates. More specifically, the present invention covers plasticcompositions containing polyacrylates and certain bis-phenoxy compounds(hereinafter defined) as fiame retardants for said plastic compositions.

Polyacrylates and utility thereof are known in the art as exemplified byArcylic Resins, M. B. Horn (Reinhold Plastics Applications Series),Reinhold Publishing Corporation, New York, 1960 and Encyclopedia ofPolymer Science and Technology, vol. 1, pp. 246-328, John Wiley & Sons,Inc., New York, 1964 and which publications are in toto incorporatedherein by reference.

The need for flame retarding polyacrylates has also been recognized inthe art as exemplified by the two abovedescribed publications and by US.3,422,048 which is incorporated hereinby reference.

The resultant disadvantages in the utilization of various prior artmaterials as flame retardants for polyacrylates include withoutlimitation, factors such as thermal migration, heat instability, lightinstability, non-biodegradable,

toxicity, discoloration and the large amounts employed in order to beeifective.

Thus, there is always a demand for a material which will function as aflame retardant in polyacrylates and concurrently will not, byincorporation therein, adversely effect the chemical and/or physicaland/or mechanical properties of the resultant composition.

The prior art problem of providing a flame retarded polyacrylatecomposition having desired chemical, physical and mechanical propertieshas now been substantially solved by the present invention and theabove-described disadvantages substantially overcome.

Accordingly, one of the main objects of the present invention is toprovide polyacrylate compositions which are flame retarded.

Another object of the present invention is to provide a material forpolyacrylate compositions which will not substantially adversely effectthe chemical and/ or physical and/or mechanical properties of saidcompositions.

A further object of the present invention is to provide a flameretardant which is economic and easy to incorporate into polyacrylatewithout being degraded or decomposed as a result of blending orprocessing operations.

It has been found that the foregoing objects can be obtained by theincorporation of a new class of bisphenoxy compounds in polyacrylates tosubsequently provide flame retarded compositions which exhibitoutstanding chemical, physical and mechanical properties.

The bis-phenoxy compounds used in the present invention compositionshave the formula:

(I) At i' Z O-(alkyIene)-O@Z In Formula I above, Z is bromine; m and mare integers each independently having a value of 14; i and i areintegers each independently having a value of 1 or 2; alkylene is astraight or branched chain alkylene group having from 1 to 6 carbonatoms (cg. CH C H C H C Hg, C5H1O, C6H12 and d A IS from the group cyano(-CH), nitro (-NO lower alkoxy (e.g. OCH OC H lower alkyl (e.g. CH C H CH C H fluorine, dialkylamino e.g.

-N(C H phenyl (--C H halo-phenyl, benzyl and halo-benzyl.

In Formula I, i or i is 1 when m or m is 4, respectively.

It is to be understood that all of the compounds falling within theabove Formula I and as heretofore defined are generically describedherein as bis-phenoxy compounds.

Illustrative (but Without limitation) of some of the present inventionbis-phenoxy compounds are shown e ow:

the exemplary definitions of A, Z, i, i, m, m, and alkylene are listedin Table I.

Patented May 14, 1974 TABLE I Z m 'm' A i i Alkylene 2 2 --ON 1 1 CH2 22 F 1 1 C2114 2 2 -CN 1 1 CaHu 2 2 -ON 1 1 C2H4 2 2 --NO: 1 1 C2H 2 2 OCH: 1 1 02H; 3 3 CH1 1 1 C2H4 2 2 CH:; 1 1 CzH4 2 2 F 1 l C Hq 2 2 (CH 11 1 02H! 2 2 uHs 1 1 C2114 2 2 --COH;B1'z 1 1 C H4 2 2 -CH2CeHs 1 1 C2H42 2 -CH2CoHaBra 1 1 C2H4 3 3 -CuHaCh 1 1 C311; 3 3 F 1 1 CaHrz 2 2 -CN 22 CzH4 4 4 CN 1 1 CaHu 3 3 CoHzBra 1 1 CzHi 3 8 --NO; 2 2 CaHu 2 2 CN 11 CH (CH3) CH2 4 4 NO: 1 1 CH(CHa)CH2CH2 3 3 F 2 2 CHzCH(CHa) CHzCHg 1 1C4Hn 1 1 CH2 1 1 O 04H: 1 1 02114 In general, the bis-phenoxy compoundsare prepared by reacting a halogenated phenol with a halogenated alkaneat elevated temperatures in the presence of a basic material such asalkali metal hydroxides, carbonates, bicarbonates, oxides and hydrides.The preferred alkali metals are potassium and sodium. Where one desiresto inncrease, for example, ease of handling the reaction mass, solventssuch as ketones (e.g. acetone, methyl ethyl ketone, and methyl iso-butylketone), alcohols (e.g. methanol, ethanol, iso-propyl alcohol, butylalcohol and glycols), or aqueous solvents (e.g. water, a mixture ofwater and alcohol and a mixture of water and ketone) can be employed.The desired end product, i.e. the bisphenoxy compound, can be recoveredfrom the reaction mass via various methods such as distillation orcrystallization. Where the end product requires recovery viacrystallization, various aromatic solvents such as benzene, toluene,xylene, dichlorobenzene and the like can be used.

Specifically, the bis-phenoxy compounds are prepared according to thefollowing reactions:

2- zm OH X(alkylene) 2HX In the above reaction, X is halogen, preferablychlorine and al-kylene is the same as herein defined. Where m and m andi and i are different integers, then equivalent molar portions of theparticular halogenated phenol are used with equivalent portions ofdissimilar halogenated phenol.

The above reaction is conducted at temperatures ranging from thefreezing point of the initial reaction mass to the boiling pointthereof. Preferably the temperatures are from about 40 C. to about 200C. and more preferably from about 50 C. to about 175 C. It is to beunderstood that the reaction can be conducted under sub-atmospheric(e.g. 1/l0-8/10 atmospheres), atmospheric or super-atmospheric (e.g.1.5-10 atmospheres) pressure. Preferably, the reaction is carried out atatmospheric pressure.

The above-described processes can be carried out with conventional,readily available chemical processing equipment. For example, aconventional glass-lined vessel provided with heat transfer means, areflux condenser and a mechanical stirrer can be advantageously utilizedin practicing any of the preferred embodiments of the inventiondescribed i the ex mp es set forth h rein.

The amount of bis-phenoxy compound employed in the present inventioncompositions is any quantity which will effectively render thepolyacrylate containing composition flame retardant. In general, theamount used is from about 1% to 25% by weight, based on the total weightof the composition. Preferably, the amount employed is from about 5% toabout 20% by weight. It is to be understood that any amount can be usedas long as it does not substantially adversely effect the chemicaland/or physical and/or mechanical properties of the end polymercomposition. The amount utilized, however, is such amount which achievesthe objectives described herein.

It is to be understood that the terms polyacrylates as used herein meansacrylic polymers including acrylic acid polymers and copolymers andacrvlic ester polymers and copolymers. For example, there may bementioned materials which contain one of the repeating units C H: CHCHand -CHz- 0 O R O O R (acrylate polymers) (methacrylate polymers) where-R is an alkyl or aryl radical or (in water-soluble polymers) amonovalent cation.

Thus the polyacrylates used in the present invention compositions is anypolyacrylates herein defined and which one so desires to flame retard.It is to be understood that the polyacrylates used can be a virginmaterial, i.e. substantially free of additives such as stabilizers,plasticizers, dyes, pigments, fillers, and the like, or thepolyacrylates can have additives (such as those mentioned and describedherein) already contained therein or added concurrently with or afterthe addition of the bis-phenoxy compounds.

Another facet of the present invention relates to the use of certainmetal compounds with the bis-phenoxy compounds to promote a cooperativeeffect therebetween and thus enhance the tflame retardancy of theresultant plastic composition as compared to the flame retardancy ofeither one component used separately. These enhancing agents are fromthe group antimony, arsenic, bismuth, tin and zinc-containing compounds.Without limitation, examples of said enhancing agents include Sb O SbClSbBI'a, S1313, AS203, AS205, ZI1B04, BaJB Of -H O, 2-ZnO-3B O -3.5H Oand stannous oxide hydrate. The preferred enhancing agent is antimonytrioxide.

The amount of enhancing agent employed in the present inventioncompositions is any amount which when used with said bis-phenoxycompounds will promote a cooperative effect therebetween. In general,the amount employed is from about 1% to about 15%, preferably from about2% to about 10%, by weight, based on the total weight of plasticcomposition. Higher amounts can be used as long as the desired endresult is achieved.

It is also within the scope of the present invention to employ othermaterials in the present invention compositions where one so desires toachieve a particular end result. Such materials include, withoutlimitation, adhesion promoters; antioxidants; antistatic agents;antimicrobials; colorants; flame retardants such as those listed on pp.456458, Modern Plastics Encyclopedia, ibid. (in addition to the newclass of flame retardants described herein); heat stabilizers; lightstabilizers; pigments; plasticizers; preservatives; ultravioletstabilizers and fillers.

In this latter category, i.e. fillers, there can be mentioned withoutlimitation, materials such as glass; carbon; cellulosic fillers (woodflour, cork and shell flour); calcium carbonate (chalk, limestone, andprecipitated calcium carbonate); metal flakes; metallic oxides(aluminum, beryllium oxide and magnesia); metallic powders (aluminum,bronze, lead, stainless steel and zinc); polymers (comminuted polymersand elastomer-pl-astic blends); silica products (diatorn-aceOus earth,novaculite, quartz,

sand, tripoli, fumed colloidal silica, silica aerogel, wet processsilica); silicates (asbestos, kaolimite, mica, nepheline syenite, talc,wollastonite, aluminum silicate and calcium silicate); and inorganiccompounds such as barium ferrite, barium sulfate, molybdenum disulfideand silicon carbide.

The above mentioned materials, including fillers, are more fullydescribed in Modern Plastics Encyclopedia, ibid., and which publicationis incorporated herein (in toto) by reference.

The amount of the above described materials employed in the presentinvention compositions can be any quantity which will not substantiallyadversely effect the desired results derived from the present inventioncompositions. Thus, the amount used can be zero (0) percent, based onthe total weight of the composition, up to that percent at which thecomposition can still be classified as a plastic. In general, suchamount will be from about 0% to about 75% and specifically from about 1%to about 50%.

The bis-phenoxy compounds can be incorporated into the polyacrylates atany processing stage in order to prepare the present inventioncompositions. In general, this is undertaken prior to fabrication eitherby physical blending or during the process of forming polyacrylates perse. Where one so desired, the bis-phenoxy compounds may be micronizedinto finely divided particles prior to incorporation into thepolyacrylates.

EXAMPLE I A virgin polymethylmethacrylate plastic material (Lucite-130,a product of E. I. du Pont de Nemours and Company, Wilmington, Del., andbeing substantially free of additives) is utilized as the base resin inorder to prepare 26- formulations (plastic compositions). With theexception of formulation No. l, the particular bisphenoxy (and theantimony trioxide enhancing agent where indicated) is incorporated intothe plastic by adding both to a Brabender mixer (Plastic-Corder, TorqueRheometer, Model PLV-l50, C. W. Brabender Instruments Inc., SouthHackensack, N.J.). The mixer is equipped with a pair of roller typeblades positioned within a head provided with heat transfer means.

The resultant mixture is heated to about 300 C.; at this temperature, itis in a molten state. The percentages by weight of each componentutilized in the respective formulations are listed in Table II. Eachformulation is discharged from the mixer and upon cooling solidifies andis ground into chips. The chips are subjected to compression molding ina Wabash press by placing said chips between two platens, the bottom ofwhich contains four equal size depressions three inches by five inchesby Vs inch deep. The top platen is then placed over the bottom platenand heat transfer means supplied thereto in order to melt said chips andthus provide solid samples (after cooling) for testing.

Portions of the samples of each respective formulation (Nos. 1-26)prepared according to the above described procedure are then subjectedto two different standard flammability tests, i.e. UL 94 and ASTM D-2863-70. The UL 94 is, in general, the application of a burner to a testspecimen (strip) for a certain period of time and observation ofcombustion, burning, and extinguishment. This procedure is fully setforth in Underwriters Laboratories bulletin entitled UL 94, Standard forSafety, 1st ed., September 19-72 and which is incorporated herein byreference. ASTM No. D-2863-70 is a flammability test which correlatesthe flammability of a plastic specimen to the available oxygen in itsimmediate environment; this correlation is stated as an Oxygen Inedx,0.1. level predicated upon the percent oxygen in the gaseous mediumwhich is required to just provide a steady state of continuous burningof the plastic specimen. This ASTM method is fully described in 1971Annual Book of ASTM Standards-Part 27,

PLASTIC COMPOSITIONS CONTAINING BIS-PHENOXY COMPOUNDS Bis-phenoxyEnhanccompound ing agent Oxygen Formulation SbzOs, index,

umber Number Percent percent percent UL 94 0 0 20. 0 SB 20 0 22. 5 SB 2010 29. 0 813-1 20 0 23. 0 SB 20 10 28. 0 SE -l. 20 0 23. 5 SB 20 10 31.5 SE-(l 20 0 24. 0 SB 20 10 32. 0 SE4) 20 0 22. 5 SB 20 10 28. 5 SE-l 200 22. 0 SB 20 10 29. 5 SE-l 20 O 23. 0 SB 20 10 31. 5 SE-O 20 0 23. 5 SB20 10 32. 0 SE-O 20 0 23. 0 SB 20 10 30. 5 SE'O 20 0 24. 5 SB 20 10 32.0 SE-O 20 0 23. 5 SB 20 I0 29. 0 813-0 20 0 25. 0 SB 20 10 32. 5 811-020 10 33. 0 511-0 Referring to Table II, the bis-phenoxy compound numberrelates to the structural formulae heretofore set forth in Table I; adifference of 2% in the Oxygen Index values is considered significant;and the UL 94 values are on a graduated scale wherein the highest degreeto lowest degree of flame retardancy is respectively SE-O, SE-l, SE-2,SB and Burns.

The results shown in Table II demonstrate the unique effectiveness ofthese bis-phenoxy compound as flame retardants for polyacrylates.Specifically, formulation No. 1 (the control) had a 0.1. of 20.0 and UL94 values of SB. In the even numbered formulations, the use of theparticular bis-phenoxy compound results in a significant increase infire retardancy as measured by 01. (While these formulations also had aSB rating, UL 94, the individual UL rating has a wide range of valuesand thus the CI. number is, in this case, more indicative of increasedflame ret-ardancy.

The use of an enhancing agent such as Sb O to promote a cooperativeeffect between such agent and the bis-phenoxy compound is fullydemonstrated via the results obtained from testing the odd numberedformulations. The highest UL 94 ratings and significantly higher 01.values are obtained when using an enhancing agent.

EXAMPLE II Example I is repeated twice; once using a 10% bis-phenoxycompound level and 3% Sb O level and secondly, 15% and 5% levelsrespectively. At both levels, the 0.1L values and UL 94 ratings areslightly lower than the 20% level of Example I.

EXAMPLE III Portions of the soid samples of formulation Nos. 1-'-26prepared according to the above described procedure of Example I aresubjected to the following ASTM tests in order to ascertain otherproperties of the resultant plastic composition:

( 1) Tensile strength (at break): ASTM Test No. D638- (2) Flexuralstrength: ASTM Test No. D790-63;

(3) Flexural modulus: ASTM Test No. D790-63;

(4) Notched Izod impact: ASTM Test No. D256-56; and

(5 geat distortion temperature (HDT): ASTM Test No.

7 Each of the aforementioned ASTM tests are standard tests in the artand are utilized collectively in order to ascertain the efiicacy of apolymeric system as an overall EXAMPLE IV The procedure of Examples I,II and III are repeated except that the enhancing agent used is zincborate instead of Sb O Substantially the same results are obtained usingzinc borate as those obtained using Sb O EXAMPLE V Strip samples of eachof formulation Nos. 1 through 26 Table II, are subjected to lightstability tests via the use of a Weather-Ometer, model 25/18 W.R., AtlasElectrical Devices Company, Chicago, Ill. Utilizing an operatingtemperature of 145 F. and a 50% relative humidity, each strip issubjected to 200 hours of simulated daylight via the use of a carbonarc. The results show that after 200 hours, there is no significantdiscoloration in any strip tested and which demonstrates that thepresent invention compositions are highly resistant to deterioration bylight.

EXAMPLE VI Samples of each of formulation Nos. 1 through 26 Table II,are subjected to temperature (thermal) stability tests via the use ofthermal gravimetric analysis (TGA). This test employed the use of aThermal Balance, model TGS1, Perkin-Elmer Corporation, Norwalk, Conn.,and an electrical balance, Cahn 2580 model, Cahn Instrument Company,Paramount, Calif. The results of these tests show that the bis-phenoxycompound containing formulations had more than adequate stability formelt processing and subsequent heat aging (i.e. high temperatureapplications) and thus demonstrating that the particularly 'bis-phenoxyare quite compatible with the plastic material. The bis-phenoxy compoundstability thus aids in providing sufiicient flame retardancy at theplastic decomposition temperature. This test also demonstrates thatthese compounds do not exhibit migration.

In view of the foregoing examples and remarks, it is seen that theplastic compositions, which incorporate these compounds, possesscharacteristics which have been unobtainable in the prior art. Thus, theuse of these compounds in the above described plastic material as flameretardants therefor is quite unique since it is not possible to predictthe effectiveness and functionality of any particular material in anypolymer system until it is actively undergone incorporation therein andthe resultant plastic composition tested according to various ASTMStandards. Furthermore, it is necessary, in order to have commercialutility, that the resultant flame retarded plastic composition possesscharacteristics such as being nontoxic. Use of these compounds in theplastic material has accomplished all of these objectives.

The above examples have been described in the foregoing specificationfor the purpose of illustration and not limitation. Many othermodifications and ramifications will naturally suggest themselves tothose skilled in the art based on this disclosure. These are intended tobe comprehended as within the scope of this invention.

What is claimed is:

1. A plastic composition containing a polyacrylate having incorporatedtherein an effective amount of a flame retardant which is a bis-phenoxycompound having the formula:

wherein Z is bromine; m and m are integers having a value of 1-4; i andi' are integers having a value of 1 or 2; alkylene is a straight orbranched chain alkylene group having from 1 to 6 carbon atoms; and A isselected from the group consisting of cyano, nitro, lower alkoxy, loweralkyl, fluorine, dialkylamino, phenyl, halophenyl, benzyl, orhalo-benzyl, with the proviso that when m or m is 4, i or i respectivelyis 1.

2. The composition as set forth in claim 1 wherein i and i are both 1.

3. The composition as set forth in claim 1 wherein i and i are both 2.

4. The composition as set forth in claim 2 wherein A is cyano.

5. The composition as set forth in claim 2. wherein A nitro. 6. Thecomposition as set forth in claim 2 wherein A lower alkoxy. 7. Thecomposition as set forth in claim 2 wherein A lower alkyl. 8. Thecomposition as set forth in claim 2 wherein A fluorine. 9. Thecomposition as set forth in claim 2 wherein A dialkylamino. 10. Thecomposition as set forth in claim 2 wherein A phenyl. 11. Thecomposition as set forth in claim 2 wherein A halo-phenyl. 12. Thecomposition as set forth in claim 2 wherein A benzyl. 13. Thecomposition as set forth in claim 2 wherein A halo-benzyl. 14. Thecomposition as set forth in claim 1 wherein alkylene is CH 15. Thecomposition as set forth in claim 1 wherein alkylene is C H 16. Thecomposition as set forth in claim 1 wherein alkylene is C H 17. Thecomposition as set forth in claim 1 wherein alkylene is C H ReferencesCited UNITED STATES PATENTS 3,385,819 5/1968 Gouinlock 260-45.75 R3,560,441 2/1971 Schwarcy ct al. 260-457 R 3,658,634 4/1972 Yanagi et al161-403 3,717,609 2/1973 Kutner 260-4595 G MAURICE I. WELSH, 111.,Primary Examiner US. Cl. X.R.

260-41 R, 41 A, 41 B, 41 C, 45.75 R, 45.75 K, 45.95 G, 613 B, Dig. 24

